Adipokines in hereditary breast cancer patients and healthy relatives

Resistin and omentin in breast cancer: A systematic review and meta-analysis

Breast cancer (BC) is the most frequently diagnosed cancer and a leading cause of cancer-related mortality among women globally. Resistin, omentin and ghrelin, adipokines involved in inflammation and metabolic regulation, have been implicated in cancer development, yet their associations with BC remain unclear. This systematic review and meta-analysis aimed to elucidate the relationships between resistin, omentin, and ghrelin concentrations and BC, while exploring potential moderators such as body mass index (BMI) and menopausal status. A comprehensive search of electronic databases up to 13 May 2024 identified studies comparing resistin and omentin, but not ghrelin, concentrations in BC patients and healthy controls. Standardized mean differences (SMDs) were calculated using random-effects models, and meta-regression and subgroup analyses were performed to investigate sources of heterogeneity. Analysis of 11 studies showed that BC patients exhibited significantly higher resistin concentrations compared to controls, with a pooled SMD of 2.05 (95 % CI 1.24 to 2.86, p < 0.001). Meta-regression indicated that BMI significantly moderated the resistin-BC association (p = 0.003). In contrast, omentin concentrations presented a complex picture, with a pooled SMD of -0.27 (95 % CI -1.39 to 0.84, I^2 = 96.2 %, p < 0.001), indicating substantial heterogeneity and inconclusive results, whereas only one study investigated ghrelin. Our findings support a significant association between elevated resistin concentrations and BC, suggesting a potential role of resistin in BC pathophysiology. The data on omentin and ghrelin remain inconclusive, warranting further investigation. Future research should focus on large, longitudinal studies with standardized methodologies to validate these findings and clarify the role of adipokines in BC.

Targeting Adiponectin in Breast Cancer

Obesity and breast cancer are two major health issues that could be categorized as sincere threats to human health. In the last few decades, the relationship between obesity and cancer has been well established and extensively investigated. There is strong evidence that overweight and obesity increase the risk of postmenopausal breast cancer, and adipokines are the central players in this relationship. Produced and secreted predominantly by white adipose tissue, adiponectin is a bioactive molecule that exhibits numerous protective effects and is considered the guardian angel of adipokine. In the obesity-cancer relationship, more and more evidence shows that adiponectin may prevent and protect individuals from developing breast cancer. Recently, several updates have been published on the implication of adiponectin in regulating tumor development, progression, and metastases. In this review, we provide an updated overview of the metabolic signaling linking adiponectin and breast cancer in all its stages. On the other hand, we critically summarize all the available promising candidates that may reactivate these pathways mainly by targeting adiponectin receptors. These molecules could be synthetic small molecules or plant-based proteins. Interestingly, the advances in genomics have made it possible to create peptide sequences that could specifically replace human adiponectin, activate its receptor, and mimic its function. Thus, the obvious anti-cancer activity of adiponectin on breast cancer should be better exploited, and adiponectin must be regarded as a serious biomarker that should be targeted in order to confront this threatening disease.

The Role of Circulating Adiponectin and SNP276G>T at ADIPOQ Gene in BRCA-mutant Women

BACKGROUND

Environmental factors may influence the lifetime risk of cancer (penetrance) in women with a BRCA mutation.

MATERIALS AND METHODS

In 89 BRCA-mutant women, affected or unaffected by breast/ovarian cancer, we explored serum levels of adipokines and their relation with the polymorphism SNP276G>T as modulators of BRCA penetrance.

RESULTS

Affected women had significantly lower adiponectin than healthy women. Affected women with rs1501299 TT had significantly lower adiponectin and higher leptin than GT and GG genotypes. GT genotype was significantly associated with the disease status [odds ratio (OR)=3.24, 95% confidence interval (95% CI)=1.03-10.17]. Women in the lower tertile of serum adiponectin had a RR of BRCA-associated cancer of 2.80, 95% CI=1.1-7.1 (p for trend=0.03) compared with women in the higher tertile.

CONCLUSION

In the SNP rs1501299 the T allele was significantly associated with lower serum levels of adiponectin in affected women, suggesting that the T allele might be related to cancer.

Attribution of Ghrelin to Cancer; Attempts to Unravel an Apparent Controversy

Ghrelin is an endogenous peptide hormone mainly produced in the stomach. It has been known to regulate energy homeostasis, stimulate secretion of growth hormone, and mediate many other physiologic effects. Various effects attributed to ghrelin contribute to many aspects of cancer development and progression. Accordingly, a large body of evidence has emerged about the association of ghrelin with several types of cancer in scales of cell-line, animal, and human studies. However, existing data are controversial. This controversy occurs in two main domains: one is the controversial results in local effects of ghrelin on different types of human cancer cell-lines; the second is the apparent disagreement in the results of in-vitro and clinical studies that investigated ghrelin association to one type of cancer. These inconsistencies have hampered the indications to consider ghrelin as a potential tumor biomarker or therapeutic agent in cancer patients. Previous studies have reviewed different parts of current literature about the ghrelin-cancer relationship. Although they have highlighted these controversial results in various ways, no specific recommendations have been given to address it. In this study, we comprehensively reviewed in-vitro, in-vivo, and clinical studies and attempted to use the following approaches to unravel the inconsistencies detected: (a) to distinguish local and systemic effects of ghrelin in interpreting its summary clinical role in each cancer; (b) scrutinizing factors that regulate local effects of ghrelin and could justify different effects of ghrelin on different cancer cell-lines. These approaches could have notable implications for future in-vitro and clinical studies.

Adipokines as therapeutic targets in breast cancer treatment

INTRODUCTION

Adipocytes, which represent a substantial part of the tumor microenvironment in breast cancer, secrete several adipokines that affect tumorigenesis, cancer progression, metastasis, and treatment resistance via multiple signaling pathways. Areas covered: In this review, we focus on the role of leptin, adiponectin, autotaxin, and interleukin-6 in breast cancer initiation, progression, metastasis, and drug response. Furthermore, we investigated adipokines as potential targets of breast cancer-specific drugs. Expert opinion: Adipokines and adipokine receptors are deregulated in breast cancer. Adipokines play various roles in breast cancer initiation, progression, metastasis, and drug response, hence, adipokine signaling could be an effective drug target. Several clinical trials are in progress to test the efficacy of adipokine targeting agents. However, adipokines also affect metabolic homeostasis; hence, the adverse effects of the targeted drug should be investigated and addressed.